Beckett glanced across at Castle. She didn't like this plan, but they had no time to think of a better one. At least it was more practical than most of the ideas Castle had suggested, which had ranged from blessing the clouds so it would rain holy water to putting out an announcement that the Winchesters would be in an empty building and then having all the demons that turned up battle it out in an organised fight club. Not much more practical, though.

The signal sounded. That was their cue. Beckett raised the salt gun in readiness to fire if it was necessary, covering Castle's back as he carefully spray-painted a devil's trap on the ground beside the basement window. His hand shook slightly, but the finished symbol was a perfect replica of what they had been taught. Beckett knew that his arms were hurting, and it didn't help that he had to spray with his left hand because of the cast on his right. She wanted to take the can from him and do it herself, but she knew his injured shoulders couldn't take the kick of a shotgun. They needed someone able-bodied ready to fire if a demon found them.

They couldn't take on a hundred demons. That had been obvious from the beginning. Beckett had seen the fight between Sam and Cas and the two demons, and the demons had put up a serious fight. And Cas was an angel. In a fight with an inexperienced hunter like Beckett or Ryan or Esposito, there would be no question about who would win. It wouldn't even be worth turning up. Not to mention the fact that Castle was injured, and would have even less of a chance, but they need him there just to make up numbers.

Dean had said it when he was having his strategy meeting with Sam and Castiel. "There are seven of us, four of us aren't hunters, and one of us is injured. We can't fight."

"Two, Dean, two of us are injured," Sam had said.

Dean had steadied himself on the back of the sofa and ignored his brother. "We need to somehow get them to leave."

"I could," Cas had started, but Dean had cut him off.

"No one is throwing themselves in front of a bus today, Cas."

Castle had attracted Beckett's attention then, waving a piece of pizza in front of her face, and she had let herself be drawn back into the conversation. Castle was getting his colour back, the twinkle coming back into his eye despite the pain in his shoulders and the situation waiting outside, and Beckett found she was reassured despite herself. She listened patiently to his crazy plans for staving off impending doom, and even contributed some points herself. She knew that the Winchesters wouldn't actually take up any of the plans, but the crazier the plan was, the easier it was to pretend that it wasn't really happening.

Now, as she watched Castle's back in the dark, she kind of wished they had gone for one of those plans. Cas had caused a thunderstorm before; surely it wouldn't be that hard for him to make it rain holy water. From the sounds of things, there would be a lot less blood involved in that plan.

It was hard to see the devil's trap on the ground. The dark red spray paint blended in with the rough dirt between the houses, and everything looked grey in the dark. It was darker than usual for New York. Maybe it was because they were out of the central city, in a part of town where the majority of the streetlights were broken. Maybe it was just the weather, the moon covered by thick clouds. But it felt like more than that. Beckett fingered the anti-possession charm around her neck and told herself she was imagining things. The sky did not get darker when something bad was about to happen. It was ridiculous.

Beckett and Castle moved around to the next window, around the back of the house. Castle painted the sign on the concrete pavers in the tiny, dirty yard, and Beckett shone her penlight over it to check it was intact before moving on to the next possible exit from the house. Check and repeat, check and repeat, for every door and window.

They left the front door free of traps. The demons needed a way in. She could hear nothing inside, and wasn't sure if that was a good thing or not. She watched as Castle hid the spray can in a bunch of weeds beside the house. It was nearly empty. So there was a good use for spray paint. She knew what she was going to do with the next can of spray paint she confiscated from a troubled teenager trying to make his mark on the world.

Beckett and Castle moved out of sight, around the corner. They sat in the single overgrown bush that they had been hiding in before the first signal, and waited.

"Hey, Castle," Beckett said quietly. She wasn't really sure how to start this conversation. Talking about feelings was not something she was good at. She brushed aside a branch that was jabbing into her side. "I just wanted to say..." she paused, trying to find the right words. If the plan didn't work and New York really did turning into a battleground of demon warfare, she wanted Castle to know what he meant to her. "You're a really good friend. Probably my best friend, and I want you to know..."

"Why, Beckett, are you giving me the last night on earth speech?" Castle quirked an eyebrow at her, wearing that cheeky little grin that always made her heart - no, wait, did nothing for her, nothing at all.

Beckett spluttered, whacking him softly in the head. "Hey, I'm just taking pity on you here."

Castle reached across and took her right hand in his left. She'd never noticed how big it was before. It practically swallowed hers. She squeezed his hand gently, careful to avoid his scraped knuckles.

Castle looked at her, his face suddenly serious. "Beckett," he said, "Kate. When this is over, we should - "And then the second signal sounded, cutting off the end of his sentence.

Beckett squeezed Castle's hand a final time, and felt his answering squeeze. Together, they crawled forward, peering out of the bush.

She stood up, helping Castle up after her, and walked towards the door they had left unprotected. Suddenly, the implications of what they were about to do hit her. It started to sink in that there was a very real possibility that people would die tonight, and if the plan didn't work –well, she didn't even want to think about it. Her chest constricted as she remembered she hadn't said a proper good-bye to Ryan and Esposito. She'd never even told them how much she valued them as both team-members and friends. It was just something she never spoke out loud. And now they were off enticing witches to follow them to the house. Bait. That's what they were. What if they never came back, and she'd never let them know?

Castle looked down at her. "Ryan and Esposito will be fine. They're good cops," he told her, almost like he was reading her mind." He took her hand once more. "Beckett, tonight we are going to kick some supernatural ass. Try to look a little excited." They walked inside, hand in hand.

The inside of the house was brightly lit and surprisingly clean. For some reason it seemed wrong. Beckett had been kind of expecting darkness and dirt, ripped wallpaper and suspicious stains. Instead, she found an old but well cared-for building that had clearly once been someone's home, and it didn't match with her expectations of the site of a demonic battleground. Until she was inside, peering around at the pleasant, unfurnished living-room with the horrendously ugly carpet, she hadn't been aware she had expectations of what a demonic battleground looked like. She hadn't even believed in demons until two days ago, why would she? She peered around. It looked exactly as though it was waiting for a real estate agent to show potential buyers around, except for the thick line of salt across the window sills.

"Oh good, you're here," Sam poked his head around a door. "Come on down."

Beckett followed him down a steep set of stairs into a basement that was edging closer to what she'd been expecting. The floor was concrete; the walls whitewashed brick, and the air damp. A bright, bare bulb hung glowing in the centre of the ceiling. The room was empty, except for a bench in the corner covered in things that Beckett wasn't sure she even wanted to know about. A devil's trap was spray painted on the floor in front of the bench, and red symbols stood out starkly on the white of the walls. The paint looked disturbingly like blood.

"Is that an altar?" Castle didn't stop to peer around, making a beeline for the bench in the corner. He prodded at a bowl, which wobbled where it was perched precariously on a stand over a black candle. Beckett could hear liquid sloshing in it, and really didn't want to know what it was. Sam and Dean both made sudden movements towards him, in useless attempts to stop anything being spilled. "I used one of these in Devil's Storm. The Satanic cult that had captured Derek Storm was trying to summon the devil. Wait - that's not what this is for, is it? Because I don't think that's a good idea."

"Trust me, dude, summoning Luci is the last thing we want to do. He's the one behind all this bounty crap." Dean sounded casual, but Beckett knew body language, and Dean was not a relaxed man.

"Wait, Satan is real? I mean really real? How do you know?" Castle absently picked up a piece of something green and herby, but wasn't really looking at it as he turned back to face the Winchesters.

Sam and Dean exchanged a look. They didn't answer the question. "Can you put that down?" Sam asked. "It's really important that everything is in exactly the right place."

"How important? If this is in the wrong place, will it make everyone sprout extra limbs or go blind or something? Because I never saw anything in my research about positioning ingredients." Castle laid the herb back on the bench, distracted for the time being.

"You ready?" Dean came over to stand beside Beckett. "You don't need to do this, you know. It's not your job. You can still back out. Take Jessica Fletcher over there and leave."

Beckett stood up a little straighter and checked her shotgun. "It's my job to protect the people of New York, even if it's from something they don't believe in," she told him. "Besides, why is it your job? Why should you be fighting these things?"

Dean chuckled wryly. "No one else will. Plus, it might not seem like it sometimes, but the world's not a bad place. Beats the alternative. Someone should fight for it."

A car door slammed outside followed by a second slam exactly ten seconds later.

"That's our signal," Dean said. "Get ready with the salt."

Upstairs, the door opened and closed. Footsteps sounded overhead, and the quiet sound of Ryan and Esposito's voices grew louder as they came down the stairs to the basement. Beckett breathed a sigh of relief as they came into view, safe and unharmed.

"How'd it go?" Dean asked as they entered.

"Everything went according to plan," Ryan informed him. He was holding a paper bag, which he handed to Sam before walking across to stand by Beckett.

"The store was a coven alright. We let them 'overhear' that we have the Winchesters captured and tied up. We've got three witches on our tail, maybe two minutes out." Esposito reported. "Castiel is distracting the nearest nest of demons, so that should give us a while with the witches before the demons start turning up."

Dean nodded. "You two stay upstairs. Make sure your guns are loaded and you've got iron chains and holy water ready. If everything works right, you shouldn't need to use them, but you should be prepared. If any demons get in, salt the front door, and don't attack unless they see you."

Ryan and Esposito checked they had everything, and came over to give Beckett the cop-gesture of solidarity, a double pat on the shoulder. They repeated the gesture with Castle, apologising when he flinched.

"Wait," said Dean, just as they were about to go through the door. "Was Cas… okay?"

"Oh yeah," Esposito said. "Last we saw, he was handing this demon its ass."

Dean smirked proudly. "Good. You guys better get upstairs."

Beckett fought off the feeling of foreboding that was invading her gut, worsened by Dean muttering something under his breath that sounded suspiciously like, "I hate this plan."

They didn't have long to wait after that. Beckett flattened herself against the wall, trying to keep out of the way until she was needed. Castle did the same on the opposite wall, offering her a smile that wasn't quite up to his usual confidence level, but helped all the same.

The witches entered as a group. Beckett was somewhat disappointed by their appearance. She'd been raised on The Wizard of Oz, and was kind of hoping that powerful witches would have the consideration to be obvious about it. Maybe not green skin and pointy hats, but a wart or two would help with identification, and she'd thought they would be old and, well, evil-looking. Castle's expression was comically disappointed. Beckett suspected it was not for the same reason as her, though. A few weeks ago, when they'd had a case involving a pagan who practiced 'witchcraft', he had espoused for some time about how witches were always young and hot, because they used their powers to take years off themselves. He'd probably been hoping for Willow and Tara from Buffy, not a trio of decidedly average looking aging hippies. These witches were middle-aged and plump. All of them had wavy hair flowing over their shoulders and wore long floating dresses. One wore glasses.

"Dean Winchester," began the glasses-wearing witch as they reached the base of the steps. "Isn't he handsome?" It wasn't really directed at anyone. Beckett couldn't really blame her, though. It was what she'd thought the first time she'd seen him without blood all over him. Out of the corner of her eye, she saw Sam roll his eyes.

The witch with the glasses made a gesture with one hand. One of the sidekick witches (Beckett could tell she was a sidekick because she was standing a little behind the witch with the glasses) began to drone in a language Beckett didn't recognise. A slight wind began to pick up inside the basement. Beckett shivered in the sudden cold.

"Wait," Sam interrupted.

The woman kept talking. A thin chain appeared from nowhere and shot towards Dean, snaking its way around his neck.

"I said wait," Sam repeated angrily, and flicked his lighter, dropping it into a bowl of herbs on the bench. A jet of blue flame shot up a foot above the bowl and immediately died back down to a faint glow.

Beckett looked back at the witches. All three were suddenly sitting bound and gagged at the base of the steps.

Dean unwound the chain from his neck. "Ladies," he said, "We have a proposition for you."

XXX

A/N: Sorry about the wait. I have just had my last uni exams ever (hopefully!). I hope you liked the chapter. It was like drawing blood from a stone.